function calc(n1: number, n2: number, fn: (n1: number, n2: number) => void) {
  fn(n1, n2)
}


calc(30, 20, function (n1, n2) {
  console.log(n1 + n2)
})

calc(30, 20, function (n1, n2) {
  console.log(n1 * n2)
})


function cump(n1:string, n2:string, fn: (a1: string , a2: string)=> void) {
  
}